The present invention relates to photoreceptor manufacturing, and more particularly, relates to a contamination-free apparatus for drying a dip coated photoreceptor or multi-layer optical photoconductive member, such as the type used in electrostatographic imaging systems.
Photoreceptors or photoconductive devices suitable for use in electrostatographic systems and machines are well known. Typically, such photoreceptors or photoconductive devices include coated photoconductive drums or coated hollow cylindrical members, that for example comprise a homogeneous coating layer of a single material such as vitreous selenium deposited onto a support substrate.
A dip coating process for manufacturing such photoconductive drums or such coated hollow cylindrical members is disclosed for example in U.S. Pat. No. 5,334,246, entitled xe2x80x9cCoated drum photoreceptor manufacturing systemxe2x80x9d issued Aug. 2, 1994 to Pietrzykowski, Jr., et al. As disclosed therein, the dip coating system features a plurality of pipes or hollow cylinder photoreceptors that are suspended from a conventional carrier means or pallet for transport through various dip coating stations in a dip coating housing. In particular, the system includes a load/unload station, a vertical transport system and a horizontal transport system for transporting the conventional carrier means or pallet having photoreceptors loaded thereon through the various processing stations. The various processes of the system thus can be completed in an in-line configuration while the photoreceptors are attached to the conventional carrier means or pallet.
Currently, the horizontal transport system for moving the coated photoreceptors through high temperature drying oven includes mechanical moving components that are in contact with load-bearing surfaces. Some such moving components are not lubricated. As a result, the horizontal transport system is often subject to failure and significant downtime due to wear and tear of the non-lubricated components. The horizontal transport system as such is therefore also subject to a shortened life, and worse yet, its mechanical components are major sources of undesirable foreign material contaminates or contamination on the photoreceptors.
There is therefore a need for a contamination-free apparatus for drying dip coated photoreceptors in a photoreceptor manufacturing process such as the dip coating system above.
Thus in accordance with an aspect of the present disclosure, there is provided a contamination-free apparatus for moving and drying coated photoreceptors. The contamination free apparatus includes an oven assembly having first and second side walls defining a heating chamber, a guiding track for guiding a photoreceptor carrier or pallet, and first and second magnetic drive loops mounted externally of said first and second side walls. Each of the first and second magnetic loops has first magnetic elements for inducing magnetic forces into the heating chamber. The contamination-free apparatus also includes a carrier or a pallet for holding coated photoreceptors for movement through the heating chamber. The carrier or pallet includes track followers, first and second end walls for facing the first and second side walls of the heating chamber, and second magnetic elements. The second magnetic elements are mounted on the first and second end walls for coupling with the first magnetic elements and thus enabling the first and second magnetic loops to magnetically move the carrier means through the heating chamber. The contamination-free apparatus further includes an air bearing assembly for holding the track followers out of contact with the guiding track as the carrier or pallet is magnetically moved through the heating chamber.